Re: 4.10 gears...not what I expected.
 

Chris,

Very interesting that you don't notice a difference with the 4:10's. Most notice a tremendous difference....

Can you get the model # of dana spicer they installed?

Also did they install a speedo correction gear? (did you get it from Marc?)

And if they did install the speedo gear, how accurate is it?

:cheers:

David

Re: 4.10 gears...not what I expected.
 

So, in reality, an identical car with 4.10 vs 3.45 gears does not necessarily accelerate quicker or harder...it actually accomplishes exactly the same thing, only requiring more engine RPM to do so? Honestly, not trying to be a smartazz here, just trying to understand. Has anybody ever timed a car to 60 or through the 1/4 before and after such a switch? I'd be interested to know because the car doesn't really "feel" any quicker. It definitely revs FASTER but doesn't feel quicker and most surprisingly, doesn't seem to spin the tires more easily. I was hoping to burn those masquerading-as-a-315 Sumitomos to the ground with one burnout!

I've gotten a little more used to it over the weekend and frankly, I sort of like the new "personality" of the car. The upper gears are more usable and the car moves away from a stop more easily, which is great. Again, this has to do with having unrealistic expections, more than anything else. Overall, I'm more surprised with the result than disappointed.

Re: 4.10 gears...not what I expected.
 

Hey bro!

Yep, I could get you the number of the gearset, I still have the box at home. I also had Marc's correction gears installed. It's different, there's no doubt. It does rev quicker and the upper gears are more useful. As I've said in other replies, I really think this has more to do with unrealistic expectations than anything else. It accelerated hard before and I expected this to increase that sensation but it didn't. It really just feels more high-strung, if that makes sense.

Re: 4.10 gears...not what I expected.
 

You should be running out of rpms in 3rd around 100+mph vs 120+mph with 3.45s, I'm around 115mph with 3.73s

Re: 4.10 gears...not what I expected.
 

http://www.carcraft.com/techarticles...s/viewall.html






Geared Up For Speed
Hot Rod did a test of gear ratios and converter sizes (smaller equals higher stall speed) versus engine rpm and quarter-mile times for their June '95 issue. We helped with the testing, so we don't feel too bad about ripping them off and reprinting the numbers here. The car used was a small-block Nova with 26-inch-tall tires. We tried four gear ratios with two TCI converters, and here's what we found:

Same Car....
3.50 gear 13.40@102.59
4.11 gear 13.18@102.81

Read more: http://www.carcraft.com/techarticles...#ixzz32C7fPvaZ

Re: 4.10 gears...not what I expected.
 

First let me say, I could take or leave the 4.10s....I would rather have $1500 in motor mods. That being said the 4.10s have:
*Less Bog on the launch
*Better accel from a roll...

I was in my 92 Zr-1(4:09) when two guys in Ducatis kept flying up on the back of the car, then backing down(we were out in the country)....after about 3 three times, the one went to haul *** past me, and when he got up close to the car I punched it....the car pulled with the bike.(it was a smaller Ducati) When we got to a stop they said they were surprised at how well the car pulled compared to the bike....to me with the 3.45 there would have been a "lag"...with the 4.09 its immediate kick in the pants throttle response.

Re: 4.10 gears...not what I expected.
 

Thanks for this. Yeah, looking at these numbers, I think that this is about the actual performance gain that I would have reasonably expected. But as I've said, in my head, I think I just blew right past expectations that were reasonable. Nobody's fault but mine.

Re: 4.10 gears...not what I expected.
 

I had a guy do a 2.59 to a 3.45 swap on an LT-1 I did head work on...after driving my 3.45 and 4.11 cars and then into the LT-1 it seemed slow....however when he got in it....he was amazed. You are right sometimes its just perspective and in your mind/expectations.

Re: 4.10 gears...not what I expected.
 

A chassis dyno won't take the gear ratio into account except that some gear selections may have more friction than others. Lets say your engine makes 300 lb/ft of torque and you run it through a 3.08 diff. The axle will see over 900 lb/ft of torque (and of course 3 times slower rpm for a conservation of energy). The chassis dyno won't read 900 lb/ft, it's a separate system with its own diameter and speed calculation. All you get is the engine torque minus the frictional losses (and whatever other fudge factors are in the mix for the dyno).

I always felt individual trans gearing would always be more useful than just the final drive, but that is not too practical in production transmissions. Take a look at the MT-82 trans in the new mustangs... 1st gear is nearly 4:1 and the 1:1 gear is actually 5th (not 4th). That's about 1/2 the reason those new Mustangs scoot so well in the 1/4. I wish the ZF had tighter ratios sometimes.

It is a time-to-distance mod, not so much a seat-of-the-pants mod. I'f I had the budget, I'd do 3.73's myself.

Re: 4.10 gears...not what I expected.
 

.22 @ 1/4 mile, I like it